Abstract: An approach for replicating changes to JSON objects uses “piecewise replication”. In piecewise replication, a piecewise update to a JSON object is replicated at a destination DBMS to a replica of the JSON object. A piecewise update changes part of JSON objects and typically changes a JSON object at the field level; a piecewise update does not overwrite an entire JSON object with an entire new JSON object, as in the full rewrite of a JSON object previously described. In piecewise replication, new values/content of the fields for change fields and a specification of the fields are transmitted from a source DBMS to a destination DBMS to effect a change to part of a JSON object.

Abstract: Techniques are described for failing over from a primary database to the replicated logical database of the primary database. Techniques are also described for the client-side object references to be preserved when failing over to the logical replica database, for AS OF and other queries preserved, and for versioning of checksums, signatures and structures across logical replicas.

Abstract: Techniques are described for preserving the inflight sessions failing over from a primary database to the replicated logical database of the primary database. In an implementation, prior to failover, when the primary database server receives a commit for a transaction, the process stores a commit indication that the transaction has been committed by performing a corresponding SQL command. The commit indication is replicated to the logical replica database by virtue of the replication of the SQL command and its execution on the logical replica database. Accordingly, the standby database server in the failover session may successfully request for the outcome of the transaction. Techniques are also described for the client-side LOB references to be preserved when failing over to the logical replica database, for AS OF queries preserved, and for versioning of checksums, signatures and structures across logical replicas.

Abstract: Techniques are described for preserving the inflight sessions failing over from a primary database to the replicated logical database of the primary database. In an implementation, prior to failover, when the primary database server receives a commit for a transaction, the process stores a commit indication that the transaction has been committed by performing a corresponding SQL command. The commit indication is replicated to the logical replica database by virtue of the replication of the SQL command and its execution on the logical replica database. Accordingly, the standby database server in the failover session may successfully request for the outcome of the transaction. Techniques are also described for the client-side LOB references to be preserved when failing over to the logical replica database, for AS OF queries preserved, and for versioning of checksums, signatures and structures across logical replicas.